This invention relates to pole-mounted birdhouses and more particularly, to a novel elevator locking and release device for releasably maintaining the birdhouse at a desired elevated position on the pole.
2. Description of the Prior Art
Birdhouses commonly are mounted at an elevated position above ground at the top of a mounting pole. In many instances the birdhouse is mounted at a considerable distance above ground which is not accessable to persons of average height. For instance, where it is desired to provide a birdhouse for habitation by Purple Martins, the house must be elevated between 10 and 15 feet above ground in order to attract the birds to the house.
Since on the one hand the house must be mounted at a considerable distance above ground to attract a desired bird, a convenient way to bring the house down to reach by an average height person must also be provided. Lowering of the house is required to clean the same, effect needed repairs as they arise, and to remove unwanted birds that may have nested. Thus, the mounting pole for the birdhouse preferably includes some elevator means for conveniently raising and lowering the house when desired.
Several types of elevator devices are available. One such device consists of two vertical poles which are hingedly connected together; lowering of the house is accomplished by pivoting the upper pole with respect to the lower one and swinging the house down. This structure is undesirable because it requires tilting of the house and may result in disturbing of birds or eggs which are present in the house when it is being lowered.
An alternate structure for lowering a birdhouse without the need for tilting the same is disclosed in applicant's U.S. Pat. No. 3,367,632 in which means are provided for lowering a birdhouse coaxial with the pole. Locking of the house on the pole is accomplished with a complex winch device, including a ratchet wheel and lever. The structure of U.S. Pat. No. 3,367,632 performs satisfactorily in use with large heavy birdhouses which require relatively heavy-duty equipment to ensure that the house does not fall once it is locked in place. For use with relatively light-weight houses, however, more economical and less complex locking devices are desired.
One structure for accomplishing locking of a birdhouse on its pole without use of a complex winch device is disclosed in Canadian Patent 929,812 issued July 10, 1973. The structure disclosed in the Canadian Patent includes a birdhouse which can be raised and lowered upon its mounting pole by a lanyard fastened to the house and run over a pulley at the top of the pole. The house has a center hole through which the pole passes. A simple rope cleat is secured to the pole near ground level and the lanyard is tied around the cleat to maintain the house in position when it is raised to the top of the pole. While this is a satisfactory method for raising and lowering the house, the rope cleat does not satisfy the need to positively secure the house in position after being raised or lowered, or to prevent accidental falling of the house as raising or lowering is effected. For example, if while raising the house the rope inadvertently is released, the house will fall with possible damage thereto or injury to the person pulling on the rope. Additionally, it is important to maintain the birdhouse at the top of the pole in an immobile position to prevent movement of the house in a horizontal plane. In the structure of the Canadian Patent referred to herein, a bracket is mounted to the ceiling of the house with slots to engage a pin mounted horizontally in the mounting post and thus prevent such undesirable rotation in the horizontal plane, If, however, through carelessness or improper procedure in fastening the lanyard to the rope cleat, the house is left a few inches lower than its extreme upper position, the slot and pin will not properly engage with the result that the house can rotate on the pole. With use of the rope cleat device, even when the house is well engaged in the slot initially, a slight stretch of the lanyard will permit the house to become disengaged with the undesired result.
The structure of the present invention obviates the aforementioned disadvantages by automatically locking the birdhouse in position at the point on the mounting pole where the lanyard is released.